Microvascular decompression of the posterior inferior cerebellar artery for intermediate nerve neuralgia

Routine postoperative admission to the neurocritical intensive care unit after microvascular decompression: necessary or can it be abandoned?

Postoperative neurocritical intensive care unit (NICU) admission of patients who underwent craniotomy for close observation is common practice. In this study, we performed a comparative analysis to determine if there is a real need for NICU admission after microvascular decompression (MVD) for cranial nerve disorders or whether it may be abandoned. The present study evaluates a consecutive series of 236 MVD surgeries performed for treatment of trigeminal neuralgia (213), hemifacial spasm (17), vagoglossopharyngeal neuralgia (2), paroxysmal vertigo (2), and pulsatile tinnitus (2). All patients were operated by the senior surgeon according to a standard protocol over a period of 12 years. Patients were admitted routinely to NICU during the first phase of the study (phase I), while in the second phase (phase II), only patients with specific indications would go to NICU. While 105 patients (44%) were admitted to NICU postoperatively (phase I), 131 patients (56%) returned to the ward after a short stay in a postanaesthesia care unit (PACU) (phase II). Specific indications for NICU admission in phase I were pneumothorax secondary to central venous catheter insertion (4 patients), AV block during surgery, low blood oxygen levels after extubation, and postoperative dysphagia and dysphonia (1 patient, respectively). There were no significant differences in the distribution of ASA scores or the presence of cardiac and pulmonary comorbidities like congestive heart failure, arterial hypertension, or chronic obstructive pulmonary disease between groups. There were no secondary referrals from PACU to NICU. Our study shows that routine admission of patients after eventless MVD to NICU does not provide additional value. NICU admission can be restricted to patients with specific indications. When MVD surgery is performed in experienced hands according to a standard anaesthesia protocol, clinical observation on a neurosurgical ward is sufficient to monitor the postoperative course. Such a policy results in substantial savings of costs and human resources.

Microvascular decompression: is routine postoperative CT imaging necessary?

BACKGROUND

Postoperative head CT imaging is routinely performed for detection of postoperative complications following intracranial procedures. However, it remains unclear whether with regard to radiation exposure, costs, and possibly lack of consequences this practice is truly justified in various operative procedures. The objective of this study was to analyze whether routine postoperative CT imaging after microvascular decompression (MVD) is necessary or whether it may be abandoned.

METHODS

A series of 202 MVD surgeries for trigeminal neuralgia (179), hemifacial spasm (17), vagoglossopharyngeal neuralgia (2), paroxysmal vertigo (2), and pulsatile tinnitus (2) operated by the senior surgeon (JKK) and who had postoperative routine CT imaging was analyzed.

RESULTS

Routine postoperative CT imaging detected small circumscribed postoperative hemorrhage in 9/202 (4.4%) instances. Hemorrhage was localized at the site of the Teflon felt (1/9), the cerebellum (4/9), in the frontal subdural space (3/9), and in the frontal subarachnoid space (1/9). In two patients, asymptomatic hemorrhage was accompanied by mild cerebellar edema (1%), and another patient had mild transient hydrocephalus (0.5%). Furthermore, there were small accumulations of intracranial air in 86/202 instances. No other complications such as infarction or skull fracture secondary to fixation with the Mayfield clamp were detected. MVD had been performed for trigeminal neuralgia in 6/9 patients, for hemifacial spasm in 2/9, and in one patient with both. No patient underwent a second surgery. Hemorrhage was symptomatic at the time of imaging in only one instance who had mild postoperative gait ataxia. Two patients with hemorrhage developed delayed facial palsy most likely unrelated to hemorrhage which remitted with corticosteroid treatment. At 3-month follow-up and at long-term follow-up, they had no neurological deficits.

CONCLUSION

Routine postoperative CT imaging is not necessary after MVD in a standard setting in patients who do not have postoperative neurological deficits.

Microvascular Decompression of the VII/VIII Cranial Nerve Complex for the Treatment of Intermediate Nerve Neuralgia: A Retrospective Case Series

BACKGROUND

Intermediate nerve neuralgia (INN) is a rare and often overlooked form of primary otalgia. The pathophysiological mechanism is unknown, although one of the possible contributing factors is a neurovascular conflict at the root entry zone of the intermediate nerve. The pain can be severely debilitating, and the palette of treatment options is small.

OBJECTIVE

To assess the outcome of microvascular decompression (MVD) of the VII/VIII cranial nerve complex for treating INN.

METHODS

We retrospectively reviewed the records of a group of 8 consecutive patients with INN who underwent MVD of the VII/VIII cranial nerve complex in the period 1994 to 2015.

RESULTS

In total, 7 of the 8 patients experienced almost immediate and complete relief of pain, which remained at long-term follow-up (mean 35 mo ± 24 mo, range 8-84 mo). Postoperatively, 1 patient had a cerebrospinal fluid (CSF) leak, 3 patients experienced permanent ipsilateral hearing loss, and 3 patients had temporary complaints associated with excessive drainage of CSF.

CONCLUSION

This study suggests MVD as a valid treatment for medically refractory INN. MVD carries surgical risk, but given the severity of complaints of these patients, we believe the treatment benefits outweigh the associated complications.

Pain-free and pain-controlled survival after sectioning the nervus intermedius in nervus intermedius neuralgia: a single-institution review

OBJECTIVE

Nervus intermedius neuralgia (NIN) or geniculate neuralgia is a rare facial pain condition consisting of sharp, lancinating pain deep in the ear and can occur alongside trigeminal neuralgia (TN). Studies on the clinical presentation, intraoperative findings, and ultimately postoperative outcomes are extremely limited. The aim of this study was to examine the clinical presentation and surgical findings, and determine pain-free survival after sectioning of the nervus intermedius (NI).

METHODS

The authors conducted a retrospective chart review and survey of patients who were diagnosed with NIN at one institution and who underwent neurosurgical interventions. Pain-free survival was determined through chart review and phone interviews using a modified facial pain and quality of life questionnaire and represented as Kaplan-Meier curves.

RESULTS

The authors found 15 patients with NIN who underwent microsurgical intervention performed by two surgeons from 2002 to 2016 at a single institution. Fourteen of these patients underwent sectioning of the NI, and 8 of 14 had concomitant TN. Five patients had visible neurovascular compression (NVC) of the NI by the anterior inferior cerebellar artery in most cases where NVC was found. The most common postoperative complaints were dizziness and vertigo, diplopia, ear fullness, tinnitus, and temporary facial nerve palsy. Thirteen of the 14 patients reportedly experienced pain relief immediately after surgery. The mean length of follow-up was 6.41 years (range 8 months to 14.5 years). Overall recurrence of any pain was 42% (6 of 14), and 4 patients (isolated NIN that received NI sectioning alone) reported their pain was the same or worse than before surgery at longest follow-up. The median pain-free survival was 4.82 years ± 14.85 months. The median pain-controlled survival was 6.22 years ± 15.78 months.

CONCLUSIONS

In this retrospective review, sectioning of the NI produced no major complications, such as permanent facial weakness or deafness, and was effective for patients when performed in addition to other procedures. After sectioning of the NI, patients experienced 4.8 years pain free and experienced 6.2 years of less pain than before surgery. Alone, sectioning of the NI was not effective. The pathophysiology of NIN is not entirely understood. It appears that neurovascular compression plays only a minor role in the syndrome and there is a high degree of overlap with TN.